Similarly specific and accurate seems the detection of prostate cancer by a recently introduced sensor chip targeting prostate cancer specific glycoproteins.
In contrast to immunoassays which are usually used for the diagnosis and monitoring of this form of cancer, the technology of researches from the University of Birmingham is easy in production, can be stored for long periods and even be recycled. Immunoassays not only are very expensive, they are sensitive to degeneration and their false-positive readings have been frequently criticized.
Convincing evidence demonstrates that, depending on the threshold and testing interval used, up to 80 percent of positive prostate-specific antigen (PSA) test results are false-positive.
Additional testing for the patient is the consequence, with one or more biopsies in the consecutive year, often accompanied by the experience of pain, infection, bleeding and other issues demanding for clinical follow-up or even hospitalization.
To overcome the constraints and disadvantages of antigen testing, the chip targeting method operates as a lock-key principle that enables only the very specific structure of prostate cancer glycoproteins to bind to a matching motif of boronic acid based carbohydrate receptors as a recognition site. In addition to a very high binding affinity, the authors report nanomolar sensitivity as well as 30-fold selectivity for prostate specific antigen over other glycoproteins.
Yet another approach presented by a group at the MD Anderson Cancer Center in Houston, might yield a potential screening opportunity for pancreatic cancer. Although this type of cancer is not as frequent as the above, it ranks fourth in the accounts for cancer deaths in the United States.
Very often, by the time of diagnosis the cancer has already spread. Curative surgery is only possible in a very small number of cases and the 5-year survival rate is only 7.2 %. A blood-test for a cancer specific exosome protein marker, however, now pointed out with a probability of 100 % those individuals who were affected by pancreatic cancer.
In contrast to low concentrations of the marker protein glypican-1 found in blood samples from healthy subjects or subjects with non-malignant inflammatory conditions of the pancreas, the marker levels were significantly increased in subjects with pancreatic cancer. The same elevation, however, was also observed for samples from patients with breast cancer.
Thus, although additional development of complementary pancreas specific profiling is clearly needed, the report gives hope that a screening biomarker for pancreatic cancer could be used for clinical purposes in the very near future.